霍山石斛多糖对人胃癌细胞生长的抑制作用

Inhibitory Effect of Dendrobium huoshanense Polysaccharides on Human Gastric Cancer Cell Growth

摘要:

研究霍山石斛多糖对人胃癌细胞SGC-7901生长的抑制作用，探讨多糖抗肿瘤作用与肿瘤相关基因表达之间的相关性。胃癌细胞SGC-7901生长的MTT检测表明，霍山石斛总多糖（DHP）、阴离子交换色谱水洗组分（DHP-1）及0.05 mol/L盐洗组分（DHP-2）能显著抑制胃癌细胞SGC-7901的生长，并呈时间和剂量依赖性，其中以DHP-2效果最好。光学及激光共聚焦显微镜观察发现，DHP-2处理过的胃癌细胞形态固缩，凋亡显著。荧光定量RT-PCR技术检测表明，DHP-2不仅能明显下调原癌基因c-myc的表达，其表达仅为对照的42.34%，而且能显著提高抑癌基因野生型p53的表达，其表达比对照高1.04倍。结果表明：霍山石斛多糖对人胃癌细胞生长的抑制作用与其组分、浓度及作用时间相关，其可能的作用机制是多糖通过下调c-myc基因和上调p53基因的表达来发挥抑制效果。

Abstract:

The research aimed to study the effect of Dendrobium huoshanense polysaccharides on the growth of human gastric cancer cell SGC-7901 and explore the correlation between the antitumor activity of polysaccharides and the expression of related genes. MTT assay of the growth of SGC-7901 cells treated with different fractions and concentrations of polysaccharides from D. huoshanense showed that total polysaccharides of D. huoshanense(DHP) and its two fractions (DHP-1 and DHP-2) could significantly inhibit SGC-7901 cells growth in a time- and dose- dependent manner. Light and laser scanning confocal microscope observation found that DHP-2 treatment caused SGC-7901 cells to become shrunk and apoptotic. qRT-PCR analysis displayed that DHP-2 not only obviously reduced the expression of gene c-myc, which were only account for 42.34% that of control, but also vastly increased the expression of gene p53, which was 1.04 fold higher than that of control. These results suggested that the inhibitory effect of D. huoshanense polysaccharides on human gastric cancer cell growth depends on its fraction, concentration and treatment time, which might be mediated by down-regulation of gene c-myc expression and up-regulation of gene p53 expression.